Furnace doors



N. C. FULLER FURNACE DOORS May 29, 1956 Filed Oct. 4, 1952 Zig.

S/DE WALL l INVENTOR NORMA/V C. Fl/L ER 'BY United States I'atenrA 0 FURNACE DGO'RSY Norman` C. Fuller, FairviewrPark, Ohio, assigner to' 'Ifhe Standard Oil Company, Cleveland, Ohio, a corporation of Chio Applicationctober 4,1952-, Serial No. 313,149

2 Claims. (Cl. 11B-176)y In wide furnaces, such as in petroleum processing plants, the prevalent type of door construction is disadvantageous, because of awkwardness of operation, and lack of adequate exposure at the top of tube-turns of the sectional oil-heating structure in the furnace. In addition the immediate vicinity of such doors is uncomfortably hot for operators. In the present invention, a construction is had which is particularly efficient, convenient, and applicable to furnaces of even very considerable width. Other objects and advantages of the present invention will be apparent from the following description.

To the accomplishment of the foregoing and related ends, the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail an illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. l is a perspective View, partly broken away, of an embodiment of the invention;

Fig. 2 is an enlarged scale perspective view of an element of the structure; and

Fig. 3 is a fragmentary side elevational `view showing the position-change in the open door relation.

In general, the construction involves a door which is mounted by hinges in a horizontal plane at its upper edge, and the width of the door is such as to correspond to the width of the furnace front, and the door contour involves an off-set, sloping forwardly and downwardly, and from the off-set the lower portion of the door extends directly downwardly. Above the hinge-line attachment, the furnace front is correspondingly off-set to provide clearance for movement of the door to a fully inverted open condition by being swung upwardly about its hinge connections; and the hoisting means for opening the door or lowering it includes a peculiar lever arm. In addition, the door structure is heat-insulative. Where a furnace is too wide for a single door to be easily manipulatable, it may be in two or more door-sections across the front, each of size convenient to lift.

As seen illustratively in Fig. l, a furnace 1 is provided with a door 2 which by a bend 3 involves an olf-set 4, the top margin thence being attached by hinges 5, which are of stand-oit form, to the furnace front 6. Above the portion 6, the furnace front recedes in shelf-like manner 7, in front-back dimension corresponding to that of the door olf-set 4. The body of the door is a heavy steel plate or boiler plate 9, and backing this is a filling of insulation held by a heat resistant metal such as stainless steel plate 11.

The operating gear for raising and lowering the door includes a cable 12 and wind-up winch 13. The cable is connected to the door by the intermediary of a channel piece of generally L-shape 14, the short leg thereof being secured to the front face of the door, as by welding, for instance, and the other or longer leg extending inside in a recess. 20 below the door in the furnace front. To the inner end of the channel 14, a exible connector 15 is pivotedA to a. pin 16, and the connector thus normally seats Within. the channel. when the door is. in closed position. Preferably, instead of being continuous to. pin- 1.6 the cable 12 is. connected by suitable eye connectors 17, I3, and an advantage, of dis-continuity of the cable line is a lessening of heat. conduction up the cable. With this construction, when the cable is woundA up by the winch 13 and the door swings. upwardly on its hinges 5, the channel I4, being fixed to the door, stands off as a lever arm which, in effect, sets the point of attachment to the door forwardly, as illustrated in Fig. 3. Center of gravity relations thus favor both stationary stages of the door position. Closing'can' be initiated by slightly moving -the door outwardly by hand.

lt is noticed that an important aspect of the invention is the safety feature provided. When the door is open and repairmen are at work, by reason of the peculiar non-drop or shelf-like construction involved the door can not fall on them. To drop the door it will be necessary to rst slightly move it outwardly by hand.

With the door in its up and open position, the endturns and pipe banks in the heating system are completely exposed frontally and at the top, thereby affording the fullest access for repairs when the furnace is shut down for such purposes. Also, otherwise in operation, it is a simple matter to quickly ascertain the conditions within, on swinging the door open.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims be employed.

I therefore particularly point out and distinctly claim as my invention:

l. In a furnace having a generally upright wall structure in which an opening is provided for access to the furnace interior, a door for closure of such opening comprising upper, intermediate and lower panels, said door being hingedly secured at its upper panel to the wall structure at the top of the opening in the latter for swinging movement about a substantially horizontal axis, the intermediate panel of the door being olf-set at an angle such that it slopes downwardly and outwardly when the door is in closed condition with the upper and lower panels being substantially vertically disposed, the furnace wall structure about such opening having a corresponding profile and above the opening being recessed to provide clearance for the door in fully open condition, the door being substantially completely inverted in moving from the closed to the fully open condition thereof, a hoisting cable suspended from a region spaced substantially vertically above the door in all positions of the latter, takeup means for said cable, and a channel member arranged and secured to the door so as to extend in closed condition of the door inwardly therebeyond at the lower door edge, said channel member in closed condition of the door opening downwardly and having the hoisting cable attached to the same only at a point spaced inwardly of the door, the cable in closed condition of the door extending from such point outwardly within the channel member and then upwardly about the lower edge of the door, the elfective terminal engagement of the cable with the door thus being shifted from the lower edge to the actual point of connection in movement of the door from closed to open condition respectively.

2. In a furnace having a generally upright wall structure in which an opening is provided for access to the furnace interior, a door for closure of such opening comprising upper, intermediate and lower panels, said door being hingedly secured at its upper panel to the wall structure at the top of the opening in the latter for swinging movement about a substantially horizontal axis,

the intermediate panel of the door being off-set at an angle such that it slopes downwardly and outwardly when the door is in closed condition with the upper and lower panels being substantially vertically disposed, the furnace wall structure about such opening having a corresponding prole and above the opening being recessed to provide clearance for the door in fully open condition, Vthe door being substantially completely inverted in moving from the closed to the fully open condition thereof, a hoisting cable suspended from a region spaced substantially vertically above the door in all positions of the latter, take-up means for said cable, and cable attaching means carried by said door and including an element which projects inwardly therebeyond when the door is in closed condition, the cable being secured to such projecting element only at a point therealong spaced inwardly from the door body and extending outwardly and upwardly about the lower edge of the door in closed condition of the latter, the effective terminal engagement of lthe cable with the door thus being shifted from the lower edge to the actual point of connection in movement of the door from closed to open condition respectively. l

References Cited in the file of this patent UNITED STATES PATENTS 512,236 Stofer Jan. 2, 1894 1,124,529 Rudd Jan. 12, 1915 1,126,080 Quigley `Tan. 26, 1915 1,495,453 St. John May 27, 1924 1,549,682 Piernay Aug. 11, 1925 2,210,854 Hagen Aug. 6, 1940 2,425,505 Benson Aug. 12, 1947 Y FOREIGN PATENTS 340,285 Great Britain Dec. 24, 1930 

1. IN A FURNACE HAVING A GENERALLY UPRIGHT WALL STRUCTURE IN WHICH AN OPENING IS PROVIDED FOR ACCESS TO THE FURNACE INTERIOR, A DOOR FOR CLOSURE OF SUCH OPENING COMPRISING UPPER, INTERMEDIATE AND LOWER PANELS SAID DOOR BEING HINGEDLY SECURED AT ITS UPPER PANEL TO THE WALL STRUCTURE AT THE TOP OF THE OPENING IN THE LATTER FOR SWINGING MOVEMENT ABOUT A SUBSTANTIALLY HORIZONTAL AXIS, THE INTERMEDIATE PANEL OF THE DOOR BEING OFF-SET AT AN ANGLE SUCH THAT IT SLOPES DOWNWARDLY AND OUTWARDLY WHEN THE DOOR IS IN CLOSED CONDITION WITH THE UPPER AND LOWER PANELS BEING SUBSTANTIALLY VERTICALLY DISPOSED, THE FURNACE WALL STRUCTURE ABOUT SUCH OPENING HAVING A CORRESPONDING PROFILE AND ABOVE THE OPENING BEING RECESSED TO PROVIDE CLEARANCE FOR THE DOOR IN FULLY OPEN CONDITION, THE DOOR BEING SUBSTANTIALLY COMPLETELY INVERTED IN MOVING FROM THE CLOSED TO THE FULLY OPEN CONDITION THEREOF, A HOISTING CABLE SUSPENDED FROM A REGION SPACED SUBSTANTIALLY VERTICALLY ABOVE THE DOOR IN ALL POSITIONS OF THE LATTER, TAKEUP MEANS FOR SAID CABLE, AND A CHANNEL MEMBER ARRANGED AND SECURED TO THE DOOR SO AS TO EXTEND IN CLOSED CONDITION OF THE DOOR INWARDLY THEREBEYOND AT THE LOWER DOOR EDGE, SAID CHANNEL MEMBER IN CLOSED CONDITION OF THE DOOR OPENING DOWNWARDLY AND HAVING THE HOISTING CABLE ATTACHED TO THE SAME ONLY AT A POINT SPACED INWARDLY OF THE DOOR, THE CABLE IN CLOSED CONDITION OF THE DOOR EXTENDING FROM SUCH POINT OUTWARDLY WITHIN THE CHANNEL MEMBER AND THEN UPWARDLY ABOUT THE LOWER EDGE OF THE DOOR, THE EFFECTIVE TERMINAL ENGAGEMENT OF THE CABLE WITH THE DOOR THUS BEING SHIFTED FROM THE LOWER EDGE TO THE ACTUAL POINT OF CONNECTION IN MOVEMENT OF THE DOOR FROM CLOSED TO OPEN CONDITION RESPECTIVELY. 